Survival in gastrointestinal tract
The environment of stomach may highly affect the survival of Lactobacilli. The survival of bacteria in gastric juice depends on their ability to tolerate low pH. The pH of excreted HCl in stomach is 0.9. However, the presence of food raises the pH value to the level of pH 3. After the ingestion of food it takes 2-4 h for the stomach to empty (Goldin and Gorbach, 1992).